Electrical connector

ABSTRACT

An electrical connector is provided with a sleeve having one section secured on a wire-crimping section of a contact member and another section extending outwardly from the wire-crimping section which has an inwardly directed annular projection having a V-shape in cross section. The annular projection is located adjacent an entrance to the wire-crimping section to define funnel means to guide a stripped end of an electrical conductor within the wire-crimping section. The annular projection has a diameter less than the diameter of the wire-crimping section to provide stop means against which the insulation engages to prevent the conductor from being improperly positioned in the connector prior to the connector being crimped to the conductor. In a modification of the invention the wire crimping section is deformed to form a projection extending axially along the wirecrimping section. This projection provides a stop against which the insulation engages.

United States Patent [.72] Inventor Woodrow William'lhoman Glen Rock.Pa. [2|] Appl. No. 17,238 {22] Filed Mar. 6. 1970 [45] Patented July 20,1971 (73] Assignee AMP Incorporated Harrisburg, Pa.

Continuation-impart of application Ser. No. 878,115, Nov. 19, 1969, nowabandoned.

[54] ELECTRICAL CONNECTOR l Claim, 7 Drawing Figs.

52 user 339/223, 339/276 511 mu ..H0lrlS/l2 50 FieldoISeal-ch 339/223,276,65

[5 6] References Cited uwmao STATES PATENTS 2,468,!69 4/1949 Carlsonetal..339/276(T)X 3,098,688 7/1963 Crimmonsetal 339/223 3,356,987 12/1967Gillespie 339/223 Primary Examiner-James A. Leppink AssistantExaminerRobert A. Hafer Au0rneys'-Curtis, Morris and Safford, William J.Keating,

Ronald D. Grefe, William Hintzc, Adrian J. LaRuc, Frederick W. Raring,Jay L. Seitchik and John Pv Vandenburg ABSTRACT: An electrical connectoris provided with a sleeve having one section secured on a wire-crimpingsection of a contact member and another section extending outwardly fromthe wire-crimping section which has an inwardly directed annularprojection having a V-shape in cross section. The annular projection islocated adjacent an entrance to the wirecrimping section to definefunnel means to guide a stripped end of an electrical conductor withinthe wire-crimping section. The annular projection has a diameter lessthan the diameter of the wire-crimping'section to provide stop meansagainst which the insulation engages to prevent the conductor from beingimproperly positioned in the connector prior to the connector beingcrimped to the conductor.

In a modification of the invention the wire crimping section is'deformedto form a projection extending axially along the wire-crimping section.This projection provides a stop against which the insulation engages.

PATENTEU JUL20I971 359471 3 INVENTOR WOODROW WILLIAM THOMAN ELECTRICALCONNECTOR This application is a continuation-in-part of copendingapplication Ser. No. 878,115, now abandoned filed Nov. l9, 1969.

This invention relates to electrical connectors and more particularly toelectrical connectors for connection onto stripped ends of electricalconductors having thin insulation.

Prior electrical connectors as disclosed in US Pat. Nos. 2,40S,l ll and3,356,987 are provided with a sleeve having one section secured onto awire-crimping section of a contact or ferrule member and this sleeveincludes an inwardly directed projection adjacent an entrance to thewire-crimping section. This projection has a diameter greater than thediameter of the wire-crimping section, and it is used as a funnel toguide the stripped end of an electrical conductor into the wire-crimpingsection with the insulation engaging the projection or the end of thewire-crimping section to limit the movement of the stripped end withinthe connector and to properly position the stripped end in thewire-crimping section.

At the present time, insulation on electrical conductors is a great dealthinner than conventional insulation, because the plastic material fromwhich the insulation is made provides the necessary protection of thewire so that thick insulation is unnecessary. This insulation is justslightly greater in diameter than that of the wire.

If the connectors disclosed in the above-identified patents are used toterminate strippedends of electrical conductors having thin insulationand no wire locator is used on the terminating means, the stripped endsof the electrical conductors are improperly positioned in thewire-crimping sections of the connectors due to the thin-walledinsulation not engaging the inwardly directed projections or the outerends of the wirecrimping sections thereby resulting in improperterminations when the wire-crimping sections are crimped onto thestripped ends.

If a wire locator is used on the terminating means and the ends of theelectrical conductors are not stripped to bare the proper length ofwire, part of the insulation will be crimped in the wire-crimpingsection which overcrimps the conductor at this location thereby workhardening the wire which provides a termination that is readilysusceptible to failure when the termination is subjected to stressessuch as, for example, tensile and vibration.

An object of the invention is to provide an electrical connector havingmeans to properly position a stripped end of an electrical conductorwithin a wire-crimping section thereof.

Another object is the provision of a sleeve having one part secured on awire-crimping section or ferrule and another part extending rearwardlyfrom the ferrule, an annular inwardly directed projection provided inthe sleeve adjacent an entrance to the ferrule and having a diameterless than the diameter of the ferrule.

A further object is to provide an inwardly directed projection means ina sleeve secured on a ferrule and located adjacent an entrance to theferrule with the projection means having a diameter less than an insidediameter of the ferrule to provide funnel means to guide a stripped endof a thin insulation conductor means into the ferrule and stop meansagainst which thin insulation engages to limit movement of the conductormeans within the sleeve and ferrule.

An additional object is the provision of an inwardly directed projectionhaving a V-shape in cross section located in an insulation supportsleeve secured onto a ferrule with the projection disposed adjacent anentrance to the ferrule and having a diameter less than the insidediameter of the ferrule.

An additional object is the provision ofa projection directly on theferrule of an electrical connector. The projection extends axially alongthe ferrule and one end serves as a stop for the thin insulation of anelectrical conductor which is inserted directly into the ferrule.

Other objects and attainments of the present invention will becomeapparent to those skilled in the art upon a reading of the followingdetailed description when taken in conjunction with the drawings inwhich there is shown and described an illustrative embodiment of theinvention; it is to be understood, however, that this embodiment is notintended to be exhaustive nor limiting of the invention but is given forpurposes of illustration in order that others skilled in the art mayfully understand the invention and the principles thereof and the mannerof applying it in practical use so that they may modify it in variousforms, each as may be best suited to the conditions ofa particular use.

In the drawings:

FIG. I is a perspective view partly broken away illustrating anelectrical connector prior to being crimped onto thin insulationelectrical conductor means;

FIG. 2 is a longitudinal crosssectional view of the electrical connectorof FIG. I with the thin insulated electrical conductor means explodedtherefrom;

FIG. 3 is a view similar to FIG. 2 with the electrical conductor meansin position within the crimping area of the electrical connector; and

FIG. 4 is a view similar to FIG. 3 with the crimping area of theelectrical connector crimped into position on the electrical conductormeans. A modification of the invention is shown in FIGS. 57.

Turning now to the drawings, an electrical connector EC is illustratedin FIGS. ll through 4 and it comprises a contact section 1 and a sleeveassembly 2. Contact section 1 is for connection with another conductivemeans and is illustrated in the form of a ring tongue and it includes awire barrel or ferrule 3 having grooves 4 axially spaced therealong.

Sleeve assembly 2 includes a metallic sleeve 5 and a dielectric sleeve 6secured thereover. Sleeve 5 is provided with a first section 7 securedalong wire barrel 3 and a second section 8 extending outwardly from wirebarrel 3 but coaxial therewith.

An inwardly directed projection 9 is formed in metallic sleeve 5adjacent the entrance to wire barrel 3. As can be discerned, inwardlydirected annular projection 9 has a V- shape in cross section and theinner and outer legs are disposed at a 45 angle with respect to thelongitudinal axis of the connector and therefore they are at rightangles with respect to each other. The inner leg of projection 9 definesan inner stop means to limit the movement of wire barrel 3 within firstsection 7 of sleeve 5, and once wire barrel 3 is positioned in section7, the end of section 7 is clinched to secure wire barrel 3 therein. Theouter leg and bight of projection 9 defines a funnel to funnel astripped end R0 of stranded insulated electrical conductor lll into wirebarrel 3. The inside diameter of projection 9, which is the bight of thelegs, is less than the inside diameter of wire barrel 3 so that the endof thin insulation 12 engages the outer leg of projection 9 therebylimiting the movement of the electrical conductor within electricalconnector EC so that stripped end Ill) is properly positioned withinwire barrel 3 which is the wire-crimping section of the electricalconnector. The inside diameter of projection 9 is however only slightlygreater than the diameter of the bared wire. Projection 9 thereforedefines funnel means to effectively funnel the stripped end 10 of theelectrical conductor II within the wire barrel even if a loose strand orstrands extend outwardly beyond the circumference of the wire and stopmeans against which the end of the thin insulation of the electricalconductor engages to limit the movement of the electrical conductorwithin the electrical connector so that the stripped end 10 can beproperly positioned within wire barrel 3 as illustrated in FIG. 3.

After the electrical conductor 11 has been properly inserted withinelectrical connector EC, the electrical connector is subjected to acrimping operation via manual or automatic crimping means to crimp thewire-crimping section consisting of wire barrel 3 and first section 7into engagement with stripped end 10 and second section 8 of sleeve 5 iscrimped into engagement with thin insulation 12 as illustrated by FIG.4. Grooves 4 enable extrusion of wire thereinto to break down oxidecoatings thereby enhancing the electrical characteristics of thetermination. The outer end of sleeve 5 is folded inside of section 8 andit is provided with a serrated edge 13 which bites into the thininsulation when the crimping operation is performed so that secondsection 8 and serrated edge 13 increase the tensile of the termination.Electrical connector EC can be provided with only sleeve 5 but it isdesirable to have dielectric sleeve 6 secured thereon and the crimpingdie is crimped through dielectric sleeve 6, which is generally made ofnylon or vinyl plastic, without any damage thereto.

Projection 9 can, of course, be formed with circumferentially spaced,inwardly directed projections.

A modification of the invention is shown in FIGSv 57. FIG. 5 shows anelectrical connector 15 for an insulated electrical conductor 16. Theconnector includes a contact section 17 and a ferrule section 18. Theferrule section 18 is deformed slightly inwardly by a blade and mandrelto form a projection including legs 19 and 20 and a bight 21 connectingthe legs together. The distance from the bight to the opposite wall ofthe ferrule is slightly greater than the bared conductor 22. Theprojection extends axially along the ferrule section 18. When the baredconductor is inserted into the ferrule section one end of the projectionforms a stop for the insulation. This limits the movement of thestripped end of the electrical conductor into the ferrule so that thebared wire of the electrical conductor is properly positioned in theferrule section. Thereafter the ferrule is crimped on the conductor witha standard crimping tool.

It will, therefore, be appreciated that the aforementioned and otherdesirable objects have been achieved; however, it should be emphasizedthat the particular embodiment of the invention, which is shown anddescribed herein, is intended as merely illustrative and not asrestrictive of the invention.

The invention I claim is in accordance with the following:

1. An electrical connector comprising a metal wire barrel, a metallicsleeve having a first section disposed over said wire barrel and asecond section extending from said first section, an annular inwardlydirected projection between said first section and said second sectionand having inner and outer legs connected together by a bight anddefining a V-shape in cross section, said bight defining an annularinner diameter smaller than the smallest inner diameter of said wirebarrel, said legs being disposed at 45 relative to a longitudinal axisofsaid connector and with respect to one another, said inner legdefining stop means for engaging said wire barrel to limit movement ofsaid barrel into said sleeve, said outer leg and said bight definingfunnel means for guiding a wire connector into said wire barrel, a wireconductor, relatively thin insulation covering said conductor, one endof said conductor being stripped and inserted through said bight andinto said wire barrel, said outer leg and said bight further definingstop means for engaging against said insulation and preventing saidinsulation to pass through said bight, said bight having an innerdiameter slightly greater that the diameter of said stripped conductorend, said conductor end being received in said wire barrel andmaintained in spaced relationship from the smallest inner diameterthereof, said first and said second sections of said sleeve beingconnected respectively to said first and said second legs, said firstsection being no larger in diameter than said second section, and adielectric sleeve receiving said metallic sleeve therein, saiddielectric sleeve having a first portion overlying said first sectionand a second portion overlying said second section, said first portionbeing no larger in diameter than said second portion.

1. An electrical connector comprising a metal wire barrel, a metallicsleeve having a first section disposed over said wire barrel and asecond section extending from said first section, an annular inwardlydirected projection between said first section and said second sectionand having inner and outer legs connected together by a bight anddefining a V-shape in cross section, said bight defining an annularinner diameter smaller than the smallest inner diameter of said wirebarrel, said legs being disposed at 45* relative to a longitudinal axisof said connector and 90* with respect to one another, said inner legdefining stop means for engaging said wire barrel to limit movement ofsaid barrel into said sleeve, said outer leg and said bight definingfunnel means for guiding a wire connector into said wire barrel, a wireconductor, relatively thin insulation covering said conductor, one endof said conductor being stripped and inserted through said bight andinto said wire barrel, said outer leg and said bight further definingstop means for engaging against said insulation and preventing saidinsulation to pass through said bight, said bight having an innerdiameter slightly greater that the diameter of said stripped conductorend, said conductor end being received in said wire barrel andmaintained in spaced relationship from the smallest inner diameterthereof, said first and said second sections of said sleeve beingconnected respectively to said first and said second legs, said firstsection being no larger in diameter than said second section, and adielectric sleeve receiving said metallic sleeve therein, saiddielectric sleeve having a first portion overlying said first sectionand a second portion overlying said second section, said first portionbeing no larger in diameter than said second portion.